Gain Enhancement of a Substrate Integrated Waveguide Slot Array for Millimeter Waves

An approach to enhance the gain of a slot antenna array located on the top wall of a substrate integrated waveguide (SIW) is investigated in this paper. The design procedure consists of two steps. We begin by designing a single slot antenna element located on the top wall of an SIW waveguide, and then we proceed to enlarge it to a full-fledged 4×5 slot array. Following this we further enhance the performance of the array by introducing a Metasurface superstrate above the antenna array. Simulation results are presented for the return loss and gain of the designed array to illustrate its performance. For the unloaded array, a low return loss of less than -10 dB is realized from 27 GHz to 34 GHz with a peak gain of 14.34 dB at 30 GHz. Up to 3 dB gain improvement is achieved, over the bare array, when a Metasurface superstrate is introduced.